CN111108794B

CN111108794B - Improvement of effective signaling of data multiplexing in demodulation reference signal and control region

Info

Publication number: CN111108794B
Application number: CN201880056563.9A
Authority: CN
Inventors: 欧麦尔·萨利姆
Original assignee: JRD Communication Shenzhen Ltd
Current assignee: JRD Communication Shenzhen Ltd
Priority date: 2017-09-11
Filing date: 2018-09-10
Publication date: 2023-10-03
Anticipated expiration: 2038-09-10
Also published as: EP3636027B1; GB2566319A; CN111108794A; GB201714570D0; GB2566319B; WO2019047957A1; US11075736B2; US20200235886A1; EP3636027A1; EP3636027A4

Abstract

The application discloses a method for transmitting data in a cell communication network. The set of resources is configured for the user equipment and a subsequent indication may be provided such that the configured set of resources is available for data transmission. An improvement in the transmission of demodulation reference signals is also provided.

Description

Improvement of effective signaling of data multiplexing in demodulation reference signal and control region

Cross reference to related applications

The present application is the national phase of international patent application PCT/CN2018/104905, filed on date 2018, 9, 10, claims priority from uk patent application No. GB 1714570.7, filed on date 11, 9, 2017, which is incorporated herein by reference in its entirety.

Technical Field

Embodiments of the present application relate generally to wireless communication systems and, more particularly, to an apparatus and method for enabling a wireless communication device, such as a User Equipment (UE) or mobile device, to access a radio access technology (Radio Access Technology, RAT) or radio access network (Radio Access Network, RAN).

Background

Wireless communication systems, such as third generation (3G) mobile telephone standards and technologies, are well known. Such 3G standards and techniques have been developed by the third generation partnership project (Third Generation Partnership Project, 3GPP for short). Third generation wireless communications are typically developed to support mobile telephone communications for macro cells. Communication systems and networks have evolved towards wider bandwidths and mobile systems.

The third generation partnership project has developed a so-called long term evolution (Long Term Evolution, LTE for short) system for mobile access networks, i.e. evolved universal mobile telecommunications system regional radio access network (Evolved Universal Mobile Telecommunication System Territorial Radio Access Network, E-UTRAN for short), in which one or more macro cells are supported by a base station called eNodeB or eNB (evolved NodeB). Recently, LTE is evolving further towards so-called fifth generation (5G) or new radio, NR, systems, where one or more cells are supported by a base station called a gNB.

A.NR service and time slot/micro time slot

The 5G standard will support a number of different services, each with very different requirements. Those services include enhanced mobile broadband (Enhanced Mobile Broadband, eMBB) for high data rate transmissions, ultra-reliable low-latency communications (Ultra-Reliable Low Latency Communication, URLLC) for devices requiring low latency and high link reliability, and mass Machine-type communications (mctc) supporting a large number of low power devices with long-life, energy-efficient communications requirements.

In order to maintain the different levels of quality of service (quality of service, qoS) requirements for these numerous services, the 5G standard must allow for flexible and scalable designs to support those various requirements at the same time.

NR supports slot-based scheduling and communication in close proximity to LTE. In addition, minislots have been standardized in NR to accommodate low latency and/or small packet size requirements. When data for URLLC service is generated at the gNB scheduler (and pre-encoded Downlink Control Information (DCI)) where slot scheduling decisions have been made, the data will be sent in micro-slot form along with its control information in order to meet low latency requirements. Multiplexing of data in the control region of the minislots is critical because of the relatively small time-frequency resources available to the minislots.

B. 3GPP design of demodulation reference Signal (Demodulation Reference Signal, abbreviated DMRS) data

For a single Orthogonal Frequency Division Multiplexing (OFDM) symbol with DMRS, there are two agreed configuration types. A first configuration type is shown in fig. 1, which is based on multiplexing two antenna ports in a comb-like manner in the frequency domain. In addition, 2 different Cyclic Shifts (CS) are utilized to allow expansion to 4 antenna ports.

Fig. 2 shows a second configuration type of frequency-domain (FD) orthogonal mask (orthogonal cover codes, OCC) based on 2 adjacent resource elements (resource elements, RE). The design support extends to 6 antenna ports.

C. NR control information based on control resource set (CORESET)

In contrast to LTE, which has an explicit time split between control (physical downlink control channel (Physical Downlink Control Channel, PDCCH) region) and data (physical downlink shared channel (Physical Downlink Shared Channel, PDSCH)) in NR, control information will be sent to users through different CORESETs in the control region. CORESET does not always occupy the entire control region due to the availability of very wide bandwidth carriers in NR. In order to achieve good spectral efficiency, NR has agreed to multiplex data on control resources. The UE is configured by the gNB to monitor one or more CORESETs, but it will not know the presence and exact location of the unconfigured CORESETs. Similarly, CORESET may be composed of certain time-frequency resources to accommodate multiple users' potential control information. But all these users may not have the control information necessary in each scheduling interval. This will result in incomplete use of CORESET, which also means an inefficient use of time-frequency system resources.

3GPP protocol for D.NR time slots and micro time slots

3GPP TR38.912 v1.0.0(2017-03)

For the same subcarriers with a regular Cyclic Prefix (CP), spaced 60kHz and below, a slot is defined as 7 or 14 OFDM symbols; for the same subcarriers with regular CPs, spaced above 60kHz, a slot is defined as 14 OFDM symbols. A slot may contain all downlinks, all uplinks or { at least one downlink portion and at least one uplink portion }. Time slot aggregation is supported, i.e., data transmissions may be scheduled to span one or more time slots.

The minislots have a length defined as follows:

-6GHz or more, supporting a minislot of length 1 symbol

Length from 2 (symbol) to slot length-1

For URLLC, at least 2 (symbols) are supported.

Above 6GHz, the minislots may begin at any OFDM symbol. The minislot contains a DMRS at a position relative to the beginning of the minislot.

● Removing support for 7-symbol slots from NR

In 14-symbol slots using non-slot based scheduling, it is allowed to have more than one defined list/unordered list (DL/UL) switch point.

Note that: CORESET monitoring periods of at least 14-symbol, 7-symbol, and 2-symbol are supported for non-slot based scheduling.

The removal of 7-symbol slots does not mean the removal of the agreed design of the 4-symbol to 7-symbol long physical uplink control channel (Physical Uplink Control Channel, PUCCH for short).

And allow for additional DMRS positions with non-slot based scheduling.

E. 3GPP protocol related to large carrier bandwidths

● From the radio access network technical specification group 1 (RAN 1) specification perspective, the maximum channel bandwidth in standard text-15 (Rel-15) for each NR carrier is 400MHz.

-note that: the final decision on the value is decided by the radio access network technical specification group 4 (RAN 4).

● From the RAN1 specification point of view, at least for the case of a single parameter set, the maximum number of sub-carriers per NR carrier in Rel-15 is candidate 3300 or 6600.

-to be studied (FFS): for the mixing parameter set, the above applies to the lowest subcarrier spacing.

-note that: the final value of the signal Bandwidth (BW) of a given channel is determined by the RAN 4.

● From the RAN1 specification point of view, the maximum number of Carrier Aggregation (CA) and Dual Carrier (DC) for NR bearers is 16.

Note that from the RAN2 specification point of view (maximum number) is considered to be 32.

The number of NR Carrier Components (CCs) in any aggregation is independently configured for downlink and uplink.

● The NR channel design should take into account the potential future extension of the above parameters in the subsequent version and allow Rel-15 UEs to access the NR network on the same frequency band in the subsequent version.

A. 3GPP protocol for control information transfer (CORESET) and search space

Protocol (RANs 1# 87):

● At least one search space included in the time/frequency resources is derived from implicit derived information of a Master Information Block (MIB)/system information/initial access information.

● The additional search space comprised by the time/frequency resources may be configured using dedicated radio resource control (Radio Resource Control, abbreviated RRC) signaling.

● Other solutions are not excluded.

Protocol (RANs 1# AH 1):

the NR supports a "group common PDCCH" carrying information such as a slot structure.

At least in the case where the gNB does not transmit the "group common PDCCH", if the UE does not receive the "group common PDCCH", the UE should be able to receive at least the PDCCH in the slot.

The network will inform the UE via RRC signaling whether to decode the "group common PDCCH".

Common does not mean that every cell must be common.

Discussion of details including "group common PDCCH" for use in Time Division Duplexing (TDD) and Frequency Division Duplexing (FDD) may continue.

The term "group common PDCCH" refers to a channel (PDCCH or separately designed channel) carrying information for a UE group.

Protocol: (RAN1#89)

● In the time domain, CORESET may be configured with one or a set of consecutive OFDM symbols.

● The configuration may indicate a starting OFDM symbol and a duration.

● CORESET is configured to correspond to only one Control Channel Element (CCE) to resource group (REG) mapping.

The working assumption is that: (RAN1#89)

● For the duration of CORESET:

● Supporting 1-3 OFDM symbols as duration of CORESET with less than or equal to X pseudo random codes (PRBs) on NR carriers

● Supporting 1-2 OFDM symbols as duration of CORESET with wider than X pseudo random codes on NR carrier

● To be studied (FFS): x value

● To be studied: other durations of time

● To be studied: relation of first PDSCH DMRS symbol to one or more symbols of CORESET for slot-based scheduling

To be studied: limitations under certain conditions

Protocol (RANs 1# AH 2):

for a 1-symbol CORESET with interleaving,

● Support at least REG bundle size=2

● The working assumption is that:

o also support REG bundle size=6

Whether the configuration between 2 and 6 is explicit or implicit

Precoder granularity in the frequency domain is equal to REG beam size in the frequency domain

For 2-symbol or 3-symbol CORESET with interleaving,

● Support at least REG bundle size = CORESET length

● The working assumption is that:

o also support REG bundle size=6

Whether the configuration between CORESET length and 6 is explicit or implicit is to be investigated

Protocol (RANs 1# AH 2):

● For CORESET configured by UE-specific higher layer signaling, at least the following is configured:

● Continuous or discontinuous frequency domain resources

● Each successive portion of CORESET is equal to or greater in frequency than the size of the REG-beam

● To be studied: accurate size and number of successive portions of CORESET

● Start OFDM symbol

● Duration of time

● If the configuration is explicit, its REG bundle size

● Transmission type (e.g., interleaved or non-interleaved)

● If contracted, more parameters can be added

● Monitoring period

● To be studied: it is the configuration of each CORESET or each or a set of PDCCH candidates

● To be studied: relation to Discontinuous Reception (DRX)

● To be studied: default/fallback value

Protocol (RANs 1# AH 2):

● The UE is configured with CORESET to monitor the group common PDCCH.

● When configured, the group common PDCCH follows the same CORESET configuration (e.g., REG-to-CCE mapping) of the CORESET.

● The group common PDCCH is formed of an integer number of CCEs.

● The CORESET of monitored group common PDCCHs carrying a Slot Format Indicator (SFI) may be the same as or different from the CORESETs of PDCCHs of other types of monitored control signaling.

B. 3GPP protocol related to control and data multiplexing

Protocol: (RAN1#87)

● The NR should support dynamic reuse of at least part of the resources in the control resource set for data of the same or different UEs at least in the frequency domain.

● If resource reuse can also be accomplished in the time domain, resource reuse is performed in the time domain

● To be studied: the real-time position of the Downlink (DL) data demodulation reference signal (DM-RS) should not be dynamically changed according to the dynamic reuse of the control resources of the data

● To be studied: time/frequency granularity for resource reuse

● To be studied: required signaling, if any

Protocol: (RAN 1 NR-Adhoc # 1)

● The starting position of the downlink data in the slot may be indicated to the UE explicitly and dynamically.

● To be studied: signaled in UE-specific Downlink Control Information (DCI) and/or "group common PDCCH

● To be studied: what the unused set of control resources can and what granularity to use for the data

Protocol: (RAN1# 88 bis)

● The duration of data transmission in a data channel may be semi-statically configured and/or dynamically indicated in a PDCCH scheduling data transmission

● To be studied: start/stop position of data transmission

● To be studied: the indicated duration is the number of symbols

● To be studied: the indicated duration is the number of time slots

● To be studied: the indicated duration is the number of symbols + slots

● To be studied: in the case of cross-slot scheduling

● To be studied: in the case of using slot aggregation

● To be studied: details of rate matching

● To be studied: when the duration of the data transmission in the data channel of the UE is unknown, whether +.

How to specify UE behavior

Protocol (RANs 1# 90):

● The UE may be configured by RRC signaling with one or more resource sets

● When the scheduled PDSCH overlaps with the resource set, the UE should assume that the scheduled PDSCH rate matches around the resource set.

● To be studied: accurate configuration of resource sets including granularity

Protocol (RANs 1# 90):

● The UE may be configured by UE-specific RRC signaling to identify the set of resources to which the PDSCH may or may not be mapped based on L1 signaling.

● For a scheduled PDSCH that overlaps with a given set of resources, L1 signaling indicates that the scheduled PDSCH rate matches or is mapped to resources around the set of resources.

● To be studied: details of L1 signaling

Protocol (RANs 1# 90):

● At least the following are supported

● When the scheduled PDSCH overlaps with the PDCCH of the scheduled PDSCH, the UE should assume that the scheduled PDSCH rate matches around the PDCCH of the scheduled PDSCH.

● Other forms of resource sharing between PDCCH and PDSCH are not precluded

C. Related proposal (TDoc) and proposal thereof

For the main point of the proposed scheme, it is proposed to configure additional data DMRS symbols in a control region, and there is no proposal like the proposed scheme. The 3GPP has a very rapid progress in last conferences in terms of provisioning resource sets through RRC signaling and then using them to dynamically multiplex data through L1 signaling. Second, the results shown in the DMRS design session and discussion, resulting in extrapolation of more than 2 symbols, can be a highly compromised conclusion. We use these two protocols/discussions to propose the proposed solution.

On the topic of data multiplexing on control resources, multiple interesting contributions are submitted to the latest R1-90 3gpp conference held at bragg.

All of the proposals described above can be accessed using the following links:

http://www.3gpp.org/ftp/tsg_ran/WG1_RL1/TSGR1_90/Docs/R1-171xxxx.Zip

the present invention seeks to address at least some of the outstanding problems in this field.

Disclosure of Invention

This summary presents related concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

According to a first aspect of the present invention, there is provided a method.

Preferably, the radio access network is a new air interface/5G network.

According to a second aspect of the present invention there is provided a base station adapted to perform the method of the other aspect of the present invention.

According to a third aspect of the present invention there is provided a user equipment adapted to perform the method of the other aspect of the present invention.

According to a fourth aspect of the present invention there is provided a non-transitory computer readable medium having stored thereon computer readable instructions for execution by a processor to perform the method of another aspect of the present invention.

The non-transitory computer readable medium may include at least one of the group consisting of a hard disk, a compact disc Read-Only Memory (CD-ROM), an optical storage device, a magnetic storage device, a Read Only Memory (ROM), a programmable Read-Only Memory (Programmable Read Only Memory PROM), an erasable programmable Read-Only Memory (Erasable Programmable Read Only Memory EPROM), an electrically erasable programmable Read-Only Memory (Electrically Erasable Programmable Read Only Memory EEPROM), and a flash Memory.

Drawings

Further details, aspects and embodiments of the invention will be described below, by way of example only, with reference to the accompanying drawings. For simplicity and clarity of illustration, elements in the figures have been illustrated and not necessarily drawn to scale. For ease of understanding, like reference numerals are used throughout the drawings.

Fig. 1 shows a first configuration type of a 1-symbol DMRS;

fig. 2 shows a second configuration type of a 1-symbol DMRS;

fig. 3 shows an example of additional DMRS positions;

fig. 4 and 5 show examples of additional DMRS in a control region.

Detailed Description

Those skilled in the art will recognize and appreciate that the specifics of the examples described are merely illustrative of some embodiments and that the teachings set forth herein are applicable in a variety of alternative scenarios.

In a new air interface (NR) system, the use of a control resource set (COntrol REsource SET, CORESET) has been agreed, which is a group of physical resource blocks (physical resource blocks, PRB) for a certain number of OFDM symbols to carry control information from the gNB to the user. The time and/or frequency portion of the extended CORESET may be significant due to the wide carrier bandwidth available for NR and may reduce system spectral efficiency if left idle. This requires multiplexing data (PDSCH) on these resources to improve spectral efficiency. The present invention proposes how to achieve reliable channel estimation for data demodulation in the control region and also discloses an efficient signaling mechanism for achieving data multiplexing in the control region.

An important element of the present invention relates to the configuration of the additional data DMRS in the control region. For data in the set of resources embedded in the control region, reliable demodulation will require the presence of channel estimates. Since the preamble DMRS may be located outside these (control) resource sets, extrapolation may be needed to prepare the channel estimate. The present invention proposes to improve the quality of channel estimation in these (control) resource sets by utilizing the DMRS of these resources (embedding the DMRS for PDCCH) or by allocating additional data (PDSCH) DMRS in these resources or a combination thereof. The invention also discloses an efficient RRC and L1 signaling to enable multiplexing of data on conventionally reserved resource sets, e.g. control transmissions. It proposes optimized signalling enabling efficient multiplexing of data around or within these resource sets, which in some cases may be preconfigured by the network. The present invention clearly exceeds the current state of the art. Not only does we propose a bitmap-based design indicating the bit mapping, but further optimized signaling is actually more important according to our understanding, 3GPP may hesitate to place a complete bitmap in DCI signaling, while some form of compressed signaling may win the protocol.

The invention has at least the following beneficial effects:

the method for improving channel estimation in resource sets (reserved conventionally for other purposes but assigned to data/PDSCH) will enable the use of higher modulation and coding strategies (Modulation and Coding Scheme, abbreviated MCS) to improve user throughput and system spectral efficiency. In the case where no additional DMRS is configured in the control region for a high fading scenario, user throughput may be severely degraded.

The present invention proposes efficient signaling to enable multiplexing of data in resource sets that traditionally have not been reserved for data (e.g. control resource set-core).

This efficient signaling allows higher throughput in terms of signaling with minimal DL control overhead.

A. Channel estimation for controlling data demodulation in a resource

In normal scheduling operation, whether slot-based or non-slot-based, 3GPP has agreed to pre-DMRS for data. In addition, in order to cover the case of a rapidly varying channel, the network may configure DMRS symbols attached to the preamble DMRS symbols. If there is one additional DMRS symbol after the pre-loaded symbol, then 3GPP is also contracted that it will be configured near the end of the slot so that there are no more than 2 data symbols after this additional DMRS symbol needs to be extrapolated. The latest protocol from 3gpp RAN1 bragg conference is shown in fig. 3: DMRS location-3 gpp R1-90 chairman reporting is attached. The main reason for this design is that the channel estimation extrapolation is less accurate than interpolation and may severely degrade the performance if done for more than 2 consecutive symbols.

Fig. 3 shows an additional DMRS location-3 gpp R1-90 chairman report.

When data is multiplexed in the control region, rate matched around CORESET or mapped into CORESET resources, the UE needs to extrapolate the data across the third or fourth OFDM symbols of the slot with the aid of the pre-loaded data DMRS located on these symbols for channel estimation. A significant delay is also introduced before the UE can process the PDSCH symbols in the control region, as it must wait until the first pre-DMRS reaches the channel estimate. If the UE only counts on the pre-loaded DMRS, the extrapolation may compromise severe user throughput and the gNB will need to use a lower MCS or the link will have an increased block error rate (BLER). The present disclosure proposes two possible solutions to overcome this problem.

i. Additional data DMRS configured in control region

In some embodiments, the data region of the UE may be extended into the control region without interfering with any CORESET or with only CORESETs known to the UE. In order to coherently demodulate the PDSCH in the control region, the UE must extrapolate its channel estimate from the PDSCH region to the control region, i.e., 1,2, or 3 symbols if the control and data regions use the same set of parameters. If the data is configured using different parameter sets with higher subcarrier spacing, extrapolation over a larger number of symbols may be required.

Fig. 4 shows a scheme of one additional data DMRS in a control region

Fig. 4 shows a reference slot of 14 symbols. Fig. 4 (a) shows a slot structure in which there are 2 CORESETs, and one user (UE 1) is configured with data starting from the 4 th OFDM symbol. The user has been configured with one DMRS symbol appended to the pre-loaded DMRS symbol. According to the 3GPP protocol, additional DMRS symbols are configured at the end of the slot. Note that this discussion is generic and independent of the number of additional DMRSs and their configuration types. Fig. 4 (b) shows a case when the gNB configures the PDSCH for the user in the control resources starting from the first symbol of the slot. The discussion remains independent if user data is multiplexed or not multiplexed within the CORESET, or if the number of CORESETs overlaps with PDSCH occurs in the control region. Now, the UE needs to extrapolate the channel estimate over the first 3OFDM symbol in fig. 4 (b). For high doppler scenarios, the channel extrapolation can be very challenging, and channel estimation errors can limit the MCS allocated to the user for which there would otherwise be a high BLER. To overcome this problem, fig. 4 (c) shows a proposed design in which the gNB has configured an additional DMRS in the control region of the user in the first OFDM symbol of the slot. Due to this additional DMRS in the control region, the user can obtain a high quality channel estimate through interpolation in the control region. An additional benefit of this DMRS symbol in the control region is an improvement in receiver processing latency. The user does not need to wait for the preamble DMRS (third or fourth OFDM symbol) to start up its receiver link. Furthermore, if there are multiple codewords and mapped in a frequency-preferential manner, the user can continue demodulation and channel decoding without waiting for the pre-loaded DMRS symbol.

In the opposite case, if additional DMRS symbols in the control region are not present, the gNB should allocate data resources on the first 2 symbols of the pre-loaded DMRS at most to avoid severely lowering the BLER (possibly less for high speed cases).

The present application proposes that the network can configure additional PDSCH DMRS symbols even before the pre-loading of data DMRS (third or fourth OFDM) symbols in the control region on the frequency resources allocated by the UE.

When the network configures an appendage PDSCH DMRS in the control region before the pre-loaded DMRS, then this is the first symbol from the user in the scheduled slot.

The present application also proposes that when the network configures the append PDSCH DMRS in the control region, it follows the same configuration type as the pre-loaded PDSCH DMRS.

The present application also proposes that when the network configures the additional PDSCH DMRS in the control region, the preamble loading and other additional DMRS symbols occupy 2 symbols, even under the constraint of the DMRS configuration type, which additional DMRS is a single symbol DMRS, so as to accommodate PDSCH antenna ports within one DMRS symbol.

This proposal would mean that if the network has been configured with the first configuration type, there would be a single additional DMRS symbol for a maximum of 4 ports in the control region, since for the first configuration type a maximum of 4 ports can be placed in one DMRS symbol. Similarly, when the DMRS adopts the second configuration type, then the gNB should configure a single additional DMRS symbol for up to 6 antenna ports in the control region.

When data uses more than one DMRS symbol in the DMRS configuration type can support the antenna ports, the gNB should configure two DMRS symbols, as the pre-loaded DMRS symbol should start from the first symbol allocated to the UE for PDSCH.

When the network maps users' data within CORESETs, the additional DMRS symbols in the control region should have pilot resource elements inside these CORESETs. In other words, the DMRS should be mapped to all frequency blocks (PRBs) that have been allocated to users in a control region.

An additional example of the proposed scheme is shown in fig. 5, fig. 5 (a) shows the setting of data DMRS symbols where UE1 and UE2 have been allocated data and are configured with only preamble loading. The data of UE1 overlaps with CORESETs of two users, while the frequency allocation of UE2 does not overlap with any CORESETs.

Fig. 5 shows additional DMRS in a control region.

In case both UEs are in low mobility condition, the configuration of pre-loading DMRS only (fig. 5 (a)) may be sufficient to perform reliable channel estimation and data demodulation/decoding. Assuming that the channel of the UE2 is rapidly changed due to the UE2 being highly mobile or having high mobility elements around it (people standing near the motorway), the gNB may configure one or two additional DMRS symbols for the UE2, fig. 5 (b) shows one additional DMRS configured at the end of the slot and one additional DMRS symbol configured in the control region on the first data symbol. Fig. 5 (c) shows the configuration of the gNB with two additional DMRS symbols (one in the middle of the slot and one at the end of the slot) in the data region and one additional DMRS symbol in the control region. The figure also shows a significant point that additional DMRS symbols (including one of the control regions) need not be configured over the entire system bandwidth. Since these are user-specific DMRSs, they are configured only on the frequency resources allocated to the relevant UE.

Control of DMRS using presence in CORESET

Another idea to improve the channel estimation quality in the control resource set for data demodulation is by using a control DMRS. This may be useful when the antenna port used for control transmission is quasi co-located (QCL) with the antenna port used for data transmission. This may also help when the gNB makes codebook-based transmissions to users, based on the control DMRS, users can extract raw channel estimates and combine them with known precoding vectors or matrices, which may estimate an effective composite channel that includes raw channels with precoding weights.

Typically, the UE knows its configured CORESET and is informed by the gNB to other (UEs), even for CORESET that is not configured to receive control information, it should be able to locate the DMRS.

The application proposes that the UE overlaps its frequency allocation by using the control DMRS (located in CORESET) to improve the channel estimation quality of data demodulation.

Applicability of the concepts to some specific system configurations

Data DMRS in control region for non-slot based scheduling: this idea of configuring additional PDSCH (data) DMRS in the control region is applicable to non-slot based scheduling when appropriate. For non-slot based scheduling, when control information comes with data that may occur for both the eMBB and URLLC users, the data may be multiplexed in the control region. If this occurs under high Doppler conditions, the gNB can configure the additional DMRS in the control region to improve channel estimation performance.

Data DMRS in a control region for Time Division Duplexing (TDD): the proposed scheme by using the control DMRS or by the network configuring the append PDSCH DMRS in the control region to improve the channel estimation is applicable to all modes of TDD, whether static or dynamic. Similarly, they are applicable to self-contained and non-self-contained architectures.

Data DMRS in control region for different configurations and numbers of DMRS symbols: the present disclosure has shown some examples with a preamble DMRS and one or two additional DMRS symbols, where each DMRS position is one OFDM symbol long. The proposed scheme of configuring additional DMRS in the control region made in the present disclosure is applicable to all data DMRS configuration types for any number of additional DMRS, 1 symbol, or two symbol pre-loaded DMRS cases.

B. Signaling of CORESET configured for user

The user may be configured to listen to one or more CORESETs, including public, group public, or user-specific sets. Instead of each of the user configured coreets to have control information for that particular user in each scheduling interval or each repetition interval of the coreets, these coreets may schedule that particular user for data at the appropriate scheduling interval.

The network may configure each user to a certain number of CORESETs, but the UE has no information about all CORESETs configured for all purposes and for all users in the cell. The 3GPP has agreed in R1-90 such that the gNB can inform the user through RRC signaling that its data rate matches around one or more resource sets when scheduled on overlapping time-frequency resources. In addition, L1 signaling is required to indicate when the scheduled PDSCH rate matches around CORESET when mapped to resources in the resource set.

As soon as RRC signaling is concerned, user specific RRC signaling has been accepted by the 3GPP to inform the user about certain resource sets (or CORESETs), the coordinates of which will be used to multiplex data in the control region. In some use cases, it may be beneficial to have this RRC signaling cell specificity if the UE is not in RRC connected state, but the gNB has some pre-indication that allows the user to become active for some time. Thus, the cell-specific RRC signaling will let the users know the time-frequency locations of the resource sets even before they are in RRC active state, and then without some delay the gNB can schedule the data of these users in the control region.

The supporting cell-specific RRC signaling informs the user about the resource set (CORESET) to enable efficient data multiplexing in the control resources.

When a user obtains knowledge of a particular number of resource sets (CORESETs) by (i) configuring to listen to control information in these CORESETs (i.e., CORESETs configured for common, group common, and specific users to the user), or (ii) explicit information through RRC signaling or other methods, it knows the locations of these CORESETs, and the gNB can multiplex the user's data around these resource sets.

Once the UE has obtained information about a certain number of resource sets, the gNB signals the user with L1 signaling whether its data is rate matched around the configured resource sets or mapped to the inside. Here two cases are distinguished:

i. the User's configured CORESET has User's control information (PDCCH) User's configured CORESET having control information (PDCCH) for the User

This covers the case of common, group common or user specific CORESET in time slots when they carry user specific control information (PDCCH). The 3GPP has agreed that when the scheduled PDSCH overlaps with the PDCCH of the scheduled PDSCH, the UE should assume that the scheduled PDSCH rate matches around the PDCCH of the scheduled PDSCH. Explicit signaling is not required to achieve this. The network may configure the frequency resources and starting symbols for PDSCH so that the UE knows that its data rate matches around its scheduled PDCCH.

The present application proposes additional L1 signaling for CORESET containing PDCCH of user, indicating to UE if its data (PDSCH) rate matches within CORESET around its CCE. This may be indicated by a single bit flag in the DCI.

The control resource set does not have control information for the user. It covers the case of co-sets for group commons and specific users when they do not carry control information for the relevant users in the time slots. Similarly, it covers the processing and signaling of resource sets that have been specifically configured for data multiplexing for the UE.

For these resource sets pre-configured to the user, if the data PDSCH frequency resource of the user overlaps with the time-frequency location of the CORESET, the gNB may implement data multiplexing around the CORESET by scheduling the activation of the data PDSCH of the user in the control region. When the user knows the time-frequency position of CORESET, the UE may not need any assumption of explicit signaling when receiving PDSCH time-frequency scheduling information, and its data rate matches around the CORESET. For the next level of data multiplexing, the gNB needs to send L1 signaling when the user's data is mapped to these resource sets.

The present application proposes to indicate additional L1 signaling to the UE, if its PDSCH is mapped in its configured set of resources, then no control information to that particular user is carried in that slot.

The design of L1 signaling indicates that the UE has its PDSCH rate matched around the configured CORESET or mapped internally in the form of a bitmap such that one bit corresponds to one configured CORESET. The value of the bits corresponding to CORESET overlapping PDSCH scheduling allows the user to learn that its data rate matches around the CORESET or maps to internal.

One possibility is that the CORESET may not carry any control information for any user, in which case the user's data may be rate matched around the CORESET's DMRS.

Another situation may occur when there is no control information in the CORESET and there is no control DMRS in the scheduling occasion. For example, this may occur when no user is configured to listen to the CORESET during the timing opportunity. In this case, there is no control DMRS for the CORESET, and the gNB may map the user's data PDSCH on all resource elements of the CORESET.

For control information for any user in the region overlapping PDSCH of a particular user when the resource set has only DMRS but no DMRS, the gNB will schedule user data and indicate to that user that its data is mapped to the resource set. A UE knowing the DMRS position of CORESET will be able to retrieve data that it maps to the set of resources and rate matches around its DMRS.

For another case, when a particular set of resources has neither control nor DMRS, the information may be sent to the user through RRC signaling while the set of resources is configured for data multiplexing. Thus, when the resource set is marked to a user whose data is to be mapped to the inside, all the resource elements inside it are used for data.

The UE may send the field in the form of a bitmap through L1 signaling, where each bit corresponds to user data scheduled inside CORESET, which may be configured to the user for potential control information arrival, or the gcb may be notified of the possibility of being dedicated to data multiplexing. When a particular bit indicates a mapping within CORESET, the user assumes that the mapping is such that:

● If the bit corresponds to a CORESET carrying the scheduling PDCCH, the PDSCH rate matches around CCEs of users within the CORESET.

● And if the resource set corresponding to the bit is not the resource set carrying the scheduling PDCCH, mapping the PDSCH into the resource set. If the mapping (the PDSCH) inside matches the rate around the DMRS of the resource set, or if all resource elements within (the resource set) are mapped with the user's data, the UE is informed to use RRC signaling first.

The UE may be configured to listen to a number of CORESETs. When the gNB wants to data transmit to the user and may need to multiplex its data in the control resources, it does not need to explicitly configure these CORESETs for data multiplexing by RRC signaling.

The CORESET, which is configured to the UE to receive control information, is not shown in the RRC signaling for data multiplexing.

In addition, the gNB may configure an additional set of resources (which may be, for example, CORESET for other users) to the user to enable efficient multiplexing of data in the control area. If dynamic L1 signaling follows a rate matching or mapping that indicates in these resource sets, the total number of CORESETs, including all CORESETs that the user is configured to receive control information and inform the resource sets for data multiplexing, may be larger than expected and these require a larger signaling load. We have the following proposed scheme to control this dynamic signaling overhead.

The gNB explicitly or implicitly informs the UE which of the known/configured resource sets (or CORESET) will send dynamic L1 signaling. Thus, dynamic L1 signaling may follow a subset of the user's known set of resources.

As described above, the L1 signaling may be in the form of a bitmap, where each individual bit is associated with a certain set of resources. For a particular user, L1 signaling is not necessarily associated with each CORESET known to the UE, but the gNB may indicate a subset of the set of resources that will send L1 signaling.

The present application has some idea of optimizing the L1 signaling associated with these resource sets.

To reduce the overhead of bitmap based signaling, where one bit is associated with a single set of resources, one optimal design of L1 signaling may be that there is only a single field in the DCI indicated to the user of the CORESET for all configurations overlapping its scheduling data (PDSCH), whether its data is rate matched or mapped into it. Another design may be to reserve one bit for CORESET containing the PDCCH of the user and 1 bit for other overlapping CORESETs.

For L1 signaling the user is informed about the mapping of the data around or within the configured set of resources, the suggested scheme for bitmap signaling and the optimized suggested scheme for compressed signaling are listed in the following table:

it will be appreciated that the application may include many more different applications, methods and embodiments than examples, and that the described embodiments are shown by way of example only.

Although not shown in detail, any device or apparatus that forms part of a network may include at least a processor, a storage unit, and a communication interface, where the processor unit, storage unit, and communication interface are configured to perform the methods of any aspect of the invention. Further options and choices are described below.

The signal processing functions of the embodiments of the present invention, in particular, the signal processor of the gNB and the signal processing circuit of the UE, may be implemented using computer systems or architectures known to those skilled in the relevant art. Computing systems, such as desktop, portable or notebook computers, hand-held computing devices (PDAs, cell phones, palmtops, etc.), mainframes, servers, clients, or any other type of special or general purpose computing device, may be used as may be suitable or suited to a particular application or environment. The computing system may include one or more processors, which may be implemented using a general-purpose or special-purpose processing engine such as a microprocessor, microcontroller, or other control processing module.

The computing system may also include a main memory, such as random access memory (random access memory, simply RAM) or other dynamic memory, for storing information and instructions to be executed by the processor. Such main memory may also be used for storing temporary variables or other intermediate information during execution of instructions to be executed by the processor. The computing system may also include a Read Only Memory (ROM) or other static storage device for the processor that stores static information and processor instructions.

The computing system may also include an information storage system, which may include, for example, a media drive and a removable storage interface. The media drive may include a drive or other mechanism to support fixed or removable storage media, such as a hard disk drive, a floppy disk drive, a magnetic tape drive, an optical disk drive, a Compact Disk (CD), a digital video drive (digital video drive, DVD), a read or write drive (read or write drive, R or RW), or other removable or fixed media drive. For example, the storage medium may include, for example, a hard disk, floppy disk, magnetic tape, optical disk, CD or DVD, or other fixed or removable medium that is read by and written to by a media drive. The storage medium may include a computer-readable storage medium having stored therein specific computer software or data.

In alternative embodiments, the information storage system may include other similar components for allowing computer programs or other instructions or data to be loaded into the computing system. For example, these components may include removable storage units and interfaces such as program cartridge to cartridge interfaces, removable memory (e.g., flash memory or other removable memory modules) to memory slots, and other removable storage units and interfaces that allow software and data to be transferred from the removable storage units to the computing system.

The computing system may also include a communication interface. Such communication interfaces may be used to allow software and data to be transferred between the computing system and external devices. In this embodiment, the communication interface may include a modem, a network interface (e.g., an ethernet or other NIC card), a communication port (e.g., a universal serial bus (universal serial bus, simply USB) port), a PCMCIA slot and card, etc. Software and data transferred via the communications interface are transferred in the form of signals which may be electronic, electromagnetic, optical or other signals capable of being received by the communications interface medium.

In this document, the terms "computer program product," "computer-readable medium," and the like may be used generally to refer to tangible media, such as memory, storage devices, or storage units. These and other forms of computer-readable media may store one or more instructions for use by a processor, including a computer system, to cause the processor to perform specified operations. These instructions, commonly referred to as "computer program code" (which may be combined in the form of computer programs or other combinations), when executed, cause the computing system to perform the functions of embodiments of the invention. Note that the code may directly cause the processor to perform certain operations, be compiled to do so, and/or be combined with other software, hardware, and/or firmware (e.g., libraries that perform standard functions) to do so.

In embodiments in which the elements are implemented using software, the software may be stored in a computer readable medium and loaded into a computing system using, for example, a removable storage drive. The control module (in this example, software instructions or executable computer program code) when executed by a processor in a computer system causes the processor to perform the functions of the invention as described herein.

Furthermore, the inventive concept may be applied to any circuit for performing signal processing functions within a network element. It is further contemplated that, for example, a semiconductor manufacturer may use the concepts of the present invention in the design of a stand-alone device, such as a microcontroller and/or any other subsystem element of a digital signal processor (digital signal processor, abbreviated DSP) or application-specific integrated circuit (application-specific integrated circuit, abbreviated ASIC).

It will be appreciated that for clarity purposes, embodiments of the present invention have been described above with reference to a single processing logic. However, the inventive concept may equally be implemented by a number of different functional units and processors to provide signal processing functionality. Thus, references to specific functional units are only to be seen as references to suitable means for providing the described functionality rather than indicative of a strict logical or physical structure or organization.

Aspects of the invention may be implemented in any suitable form including hardware, software, firmware or any combination of these. Alternatively, the invention may be implemented at least in part as computer software running on one or more data processors and/or digital signal processors or configurable module components such as FPGA devices. Thus, the elements and components of an embodiment of the invention may be physically, functionally and logically implemented in any suitable way. Indeed the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units.

Although the present invention has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the invention is limited only by the appended claims. In addition, while a feature is described in connection with particular embodiments, those skilled in the art will recognize that multiple features of the described embodiments may be combined. In the claims, the term "comprising" does not exclude the presence of other elements or steps.

Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented by e.g. a single unit or processor. In addition, although individual functions may be included in different claims, these may possibly be advantageously combined, the inclusion in different claims does not imply that a combination of functions is not feasible and/or advantageous. Likewise, the inclusion of a feature in one set of claims does not imply a limitation to this set, but rather indicates that the feature is equally applicable to other claim sets as appropriate.

Furthermore, the order of features in the claims does not imply any specific order in which the features must be performed, and in particular the order of individual steps in a method claim does not imply that the steps must be performed in this order. Rather, the steps may be performed in any suitable order. In addition, singular references do not exclude a plurality. Thus, references to "a," "an," "the first," "the second," etc. do not exclude a plurality.

Although the present invention has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the invention is limited only by the appended claims. Furthermore, although features appear to be described in connection with particular embodiments, one skilled in the art will appreciate that different features of the described embodiments may be combined in accordance with the invention. In the claims, the term "comprising" or "comprises" does not exclude the presence of other elements.

Claims

1. A method of transmitting data to a user equipment in a cellular communication network, the method comprising the steps of:

transmitting a signal to a user equipment, the signal indicating at least one set of resources configured for the user equipment;

transmitting a further indication to the user equipment indicating a set of configuration resources to which layer 1 signalling is to be transmitted to the user equipment; and

transmitting a subsequent indication to the user equipment to indicate a set of configuration resources available for transmitting data to the user equipment;

wherein the subsequent indications are sent in a bitmap such that each bit corresponds to at least one set of resources configured for the user equipment, the bitmap being sent via layer 1 signaling.

2. The method of claim 1, further comprising the step of transmitting data to the user device, wherein the data rate matches around at least one set of resources configured for the user device but is not indicated for transmitting data in the subsequent designation.

3. The method of claim 1, further comprising the step of transmitting data to the user device, wherein the data is transmitted at least in part within a set of resources indicated as configured for the user device and available for transmitting data in the subsequent designation.

4. The method of claim 1, wherein the at least one set of resources configured for the user device is a set of control resources.

5. The method of claim 1, further comprising the step of sending an indication of a subset of the set of configured resources that can be indicated as being available for transmitting data to the user device.

6. The method of claim 1, wherein the bits of the bitmap correspond to a subset of an allocated set of resources.

7. The method of claim 1, wherein the bitmap comprises two bits, a first bit related to a set of resources including PDCCH, and a second bit related to other sets of resources.

8. The method of claim 1, wherein the signal sent to the user device and the indication are sent from a gNB in a cell network to a user device connected to the cell network over a wireless communication link.

9. The method of claim 1, wherein the data is transmitted over a PDSCH channel.

10. The method of claim 1, wherein each bit of the bitmap corresponds to a set of configured resources.

11. The method of claim 1, wherein the subsequent indication is transmitted with a single bit associated with a subset of the set of configured resources.